JP2006144830A - Oldham ring, its method of manufacture, and installation plate for sintering powder metallurgical oldham ring - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure the parallelism of the end face of a powder metallurgical Oldham ring by a rather simple method in manufacturing the Oldham ring. <P>SOLUTION: This method of manufacturing the powder metallurgical Oldham ring comprises a powder molding step, a sintering step, a machining step, and a surface treatment step. In the sintering step, the upper surface 22 of a placing plate 21 for placing a work 11 formed of a pressed powder body is molded to the approximately same parallelism as that set for the Oldham ring. Since the end face 2 is brought into contact with the upper surface 2 and deformed by its own weight along the upper surface in sintering, the parallelism of the end face 2 can be set to a prescribed numerical value. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an Oldham ring, a manufacturing method thereof, and a mounting plate for sintering an Oldham ring made of powder metallurgy.

  As shown in FIG. 4, an Oldham ring, which is a part used for an Oldham shaft coupling that transmits torque between shafts whose axes are slightly displaced, is a circular cylinder whose outer peripheral surface and inner peripheral surface of an annular ring body 1 are coaxial. Both end surfaces 2 and 3 are planes orthogonal to the cylindrical surface. A pair of protruding key portions 4, 5, 6 and 7 are formed on both end faces 2 and 3 of the ring body 1, respectively. The key portions 4 and 5 on one end surface 2 are in axial symmetry with respect to the central axis of the ring body 1, and the key portions 6 and 7 on the other end surface 3 are axially symmetrical with respect to the central axis of the ring body 1. In addition, the key portions 6 and 7 have crossing angles so that the key portions 6 and 7 are located 90 ° apart from the key portions 4 and 5 with the central axis as a center. That is, the key parts 4, 5, 6, and 7 are arranged at the positions of the ten characters.

And the manufacturing method shape | molds the green compact which consists of iron powder with the powder molding press which assembled | attached the metal mold | die apparatus (powder shaping | molding process). In this powder molding step, the raw material powder is filled into the die by a feeder. Thereafter, the upper punch is lowered and fitted in the die, and the raw material powder is compressed to form a green compact. After pressing, the green compact is extracted from the die. As shown in FIG. 5, the workpiece 11 as a green compact formed in this way has a pair of protruding key portions 4 on both end surfaces 2 and 3 of the ring body corresponding portion 1 </ b> A of the workpiece 11 corresponding to the ring body 1. , 5, 6 and 7 are formed. The workpiece 11 is placed on a flat plate and heated and sintered in a sintering furnace (not shown) (sintering step). Next, the sintered workpiece 11 is recompressed and corrected by a correction press (correction process), and the flatness of both end faces 2 and 3 is adjusted to a predetermined numerical value. Next, the workpiece 11 is subjected to machining such as deburring, cutting and polishing (machining process). In this machining process, the outer peripheral portion of the work 11 corresponding to the ring body corresponding portion 1A (the portion on the outer peripheral side from the two-dot chain line R in FIG. 5) is cut to a predetermined diameter, thereby, as shown in FIG. , 5, 6 and 7 project from the ring body 1 radially outward. Further, the workpiece 11 is subjected to a steam treatment for forming an oxide film for improving wear resistance (surface treatment step).
Japanese Patent Laid-Open No. 11-193827

  In the prior art, a powder molding process, a sintering process, a correction process, a machining process, a surface treatment process, and the like are used. Of these, the flatness of the both end faces 2 and 3 is conventionally flat. The workpiece 11 after the sintering process, which is about 15/100 mm, is finished to a predetermined flatness required as an Oldham ring in the correction process, for example, 5/100 mm or less, and used as an Oldham shaft coupling part.

  In general, as shown in FIG. 6, the flatness is measured by placing one end face 2 as a surface to be measured of the work 11 using a three-point jack 13 on a surface plate 12 on which extremely high flatness is obtained. Adjust the surface parallel to the reference plane of the surface plate 12, and then move the tip of the rotating lever 14 at the end attached to the body 13 arranged at a constant angle along the end surface 2 as the surface to be measured. The turning state of the turning lever 14 generated in the above is displayed on the indicator 15, and the deviation ΔX with respect to the reference plane is read. In FIG. 5, the key portions 4, 5, 6, and 7 are omitted.

  In the manufacture of such an Oldham ring, the flatness value of the workpiece 11 after the sintering process becomes more than a predetermined value. Therefore, a correction process is performed to correct this, but the work is repeated by pressing. In the compressed and straightened workpiece, pores appearing on the surfaces of the end faces 2 and 3 are crushed, and there is a possibility that surface treatment such as steam treatment cannot be performed satisfactorily.

  The problem to be solved is that in the Oldham ring having the protruding key portions on both end faces of the annular ring body, the surface treatment layer is surely formed, and further, the workpiece made of the green compact is added. In the manufacture of powder metallurgical Oldham rings, which are placed on a mounting plate and sintered with protrusion-like key portions on both end faces, the flatness of the end face is ensured by a relatively simple method. It is a point which provides the mounting plate for sintering of the Oldham ring manufacturing method and powder metallurgy Oldham ring which can be manufactured.

  The invention of claim 1 is a powder metallurgy Oldham ring having projecting key portions on both end faces of an annular ring body, wherein a surface treatment layer is provided on the end face formed by the sintered face. It is an Oldham ring.

  The invention of claim 2 is the Oldham ring according to claim 1, wherein the powder metallurgy is iron-based powder metallurgy, and the surface treatment layer is an iron oxide film by steam treatment.

  The invention of claim 3 is a method for producing an Oldham ring made of powder metallurgy in which a green compact having protruding key portions on both end faces of an annular ring body is placed on a placing plate and sintered. An Oldham ring manufacturing method characterized in that the mounting surface of the green compact on the mounting plate is formed to have substantially the same flatness as the flatness set for the Oldham ring.

  According to a fourth aspect of the present invention, there is provided a sintering plate for a powder metallurgy Oldham ring for mounting and sintering a green compact having protruding key portions on both end faces of an annular ring body. A mounting plate for sintering an Oldham ring made of powder metallurgy, characterized in that the mounting surface of the green compact in the mounting plate is formed by machining to a flatness substantially the same as the flatness set for the Oldham ring. It is.

  According to the first aspect of the present invention, pores between the metal powders are formed on the end face, and the surface treatment layer can be reliably formed by entering the surface treatment layer into the pores.

  According to invention of Claim 2, the iron oxide film by a steam process can be reliably formed in the pore between the iron powders formed in the said end surface.

  According to the invention of claim 3, by forming the mounting surface of the green compact on the mounting plate with a flatness that is substantially the same as the flatness set for the Oldham ring, the pressure that contacts the mounting surface. The end surface of the powder is sintered in contact with the surface so as to be along the mounting surface, thereby ensuring the flatness of the end surface.

  According to the fourth aspect of the present invention, the mounting surface of the green compact on the mounting plate is formed by machining to have substantially the same flatness as the flatness set for the Oldham ring, thereby contacting the mounting surface. Flatness of the end face can be ensured by sintering by contacting the end face of the green compact so as to be along the mounting surface.

  Preferred embodiments of the present invention will be described with reference to the accompanying drawings. The embodiments described below do not limit the contents of the present invention described in the claims. In addition, all of the configurations described below are not necessarily essential requirements of the present invention.

  1 to 3 show a first embodiment, and the enlarged cross-sectional portion of FIGS. 1 and 3 is shown as a model. In the manufacturing method of the Oldham ring shown in FIG. 4 described above, the workpiece 11 as the green compact of the iron powder 20 as the metal powder formed in the powder forming process corresponds to the ring body 1 as shown in FIG. A pair of protruding key portions 4, 5, 6, and 7 are formed on both end surfaces 2 and 3 of the ring body corresponding portion 1A of the work 11, respectively.

  In the next sintering step, the work 11 is placed on the upper surface 22 as the mounting surface of the flat plate-shaped mounting plate 21 as shown in FIGS. 1 and 2, and conveyed in the sintering furnace 23 by the conveyor 24. Heated and sintered. The mounting plate 21 is a flat plate made of a heat-resistant material such as ceramic and has a substantially rectangular flat surface. The thickness Y of the mounting plate 21 is larger than the protruding length Z of the key portions 4 and 5, and both the left and right sides of the mounting plate 21. A notch groove 25 is formed in the notch groove 25, and the key portions 4 and 5 can be inserted into the notch groove 25. Further, the upper surface 22 of the mounting plate 21 is machined by polishing or cutting to form a flatness of 5/100 mm or less. Therefore, the end surface 2 is pressed so as to be in plane contact with the upper surface 22 by the dead weight of the work 11 made of iron powder 20 in the sintering process, and the end surface 2 is deformed along the upper surface 22, and as a result, the flatness state of the upper surface 22 is copied. As a result, the flatness of the end face 2 is formed to be 5/100 mm or less. Moreover, as the end face 2 is formed with a predetermined flatness, the opposite end face 3 is also formed with a flatness of 5/100 mm or less. This is because the end face 3 above the workpiece 11 which is a green compact is previously formed in parallel with the end face 2, and the end face 2 is formed with a predetermined flatness during the sintering process. The side end face 3 is also formed with a predetermined flatness.

Next, it becomes a machining process without going through a correction process. In the machining process, the outer peripheral portion of the ring body corresponding portion 1A of the work 11 (the portion on the outer peripheral side from the two-dot chain line R in FIG. 3) is cut to a predetermined diameter, thereby, as shown in FIG. 5, 6 and 7 project from the ring body 1 radially outward. At this time, both end faces 2 and 3 are formed with a predetermined flatness. Further, in the surface treatment process, the work 11 is subjected to steam treatment for improving wear resistance and the like to form iron oxide 26. At this time, the sintered iron powder 20 is not crushed because the sintered surfaces of the sintered surfaces such as the end faces 2 and 3 have not been crushed. The film (Fe ₂ O ₃ ) 26 can be reliably formed.

  As described above, in the above embodiment, the powder metallurgy Oldham ring having the projecting key portions 4, 5, 6, and 7 on the both end surfaces 2 and 3 of the annular ring body 1 is formed by the sintered surface. By providing an oxide film 26 as a surface treatment layer on the end faces 2 and 3, the iron oxide film 26 can be formed with pores 27 formed on the surfaces of the end faces 2 and 3. Can be reliably formed.

  Furthermore, the powder metallurgy is a powder metallurgy of iron powder 20, and the surface treatment layer can be easily and reliably formed by forming the iron oxide film 26 by steam treatment.

  In the manufacturing method, the upper surface 22 of the mounting plate 21 is formed in the sintering step so as to have substantially the same flatness as the flatness set for the Oldham ring so that the end surface 2 follows the upper surface 22 during sintering. The flatness of the end face 2 can be set to a predetermined numerical value by surface contact with the dead weight and deformation. If the end face 3 is formed in parallel with the end face 2 at the stage of the workpiece made of the green compact, the end face 3 is also formed to have a predetermined flatness as the end face 2 has a predetermined flatness during the sintering process. Is done.

  Moreover, the upper surface 22 as the mounting surface of the workpiece 11 made of the green compact in the mounting plate 21 is formed by machining so that the flatness is substantially the same as the flatness set for the Oldham ring. It is possible to accurately form the degree, and to bring the end face 2 in contact with the workpiece 11 into surface contact during sintering, thereby accurately forming the flatness of the end face 2 and further the flatness of the other end face 3.

  As described above, the Oldham ring, the Oldham ring manufacturing method, and the mounting plate for sintering thereof according to the present invention can be variously modified.

It is sectional drawing which expanded a part which shows Example 1 of this invention. It is a disassembled perspective view which shows Example 1 of this invention. It is the perspective view which expanded a part which shows Example 1 of this invention. It is a perspective view of an Oldham ring. It is a perspective view of a green compact. It is sectional drawing which shows the measurement of flatness.

Explanation of symbols

1 Ring body 2 3 End face 4 5 6 7 Key part
11 Workpiece (green compact)
20 Iron powder (metal powder)
21 Mounting plate
22 Top surface (mounting surface)
26 Iron oxide film

Claims (4)

  An Oldham ring made of powder metallurgy having protrusion-like key portions on both end faces of an annular ring body, wherein a surface treatment layer is provided on the end face formed by a sintered surface.   The Oldham ring according to claim 1, wherein the powder metallurgy is iron-based powder metallurgy, and the surface treatment layer is an iron oxide film by steam treatment.   In the manufacturing method of an Oldham ring made of powder metallurgy, in which a green compact having protruding key portions on both end faces of an annular ring body is placed on a mounting plate and sintered, the pressure in the mounting plate is described above. A method for producing an Oldham ring, wherein the powder mounting surface is formed to have substantially the same flatness as the flatness set for the Oldham ring.   In the sintering mounting plate of the powder metallurgy Oldham ring for mounting and sintering the green compact having the protruding key portions on both end faces of the annular ring body, the green compact in the mounting plate described above A mounting plate for sintering an Oldham ring made of powder metallurgy, characterized in that the mounting surface of the body is formed by machining to have substantially the same flatness as that set for the Oldham ring.

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